Louis Frémaux was admired for his flair, his wristy baton technique and the way he virtually danced on the podium.
Photograph: Robin Del Mar/Lebrecht

Louis Frémaux, who has died aged 95, was the only major orchestral conductor to serve two spells as an officer in the Foreign Legion. Perhaps the experience of leading some of France’s toughest, most hardbitten troops assisted him in dealing with refractory or undisciplined musicians. On the other hand, his wish to have his own way contributed to the messy end of his memorable stint in Birmingham.

Born in Aire-sur-la-Lys, northern France, into an artistic family, Frémaux attended the Valenciennes conservatoire, but his studies were disrupted by the second world war, in which he fought in the resistance. Given a commission in the Foreign Legion, he served in Vietnam in 1945-46, then entered the Paris Conservatoire – where Louis Fourestier, Jacques de La Presle, Simone Plé-Caussade and Jacques Chailley were his teachers – and graduated in 1952 with a first prize in conducting.

By 1954 he was making his mark, but he was called back to the Foreign Legion and posted to Algeria. Prince Rainier of Monaco, who wanted Frémaux for the Monte Carlo national opera orchestra, pulled strings to have him released, and Frémaux took up his post in 1956, premiering Panufnik’s Sinfonia Sacra in 1964 and greatly improving the orchestra by the time he left in 1965. In 1957 he began recording baroque music for Erato: in particular, two LPs of André Campra’s choral works, including the Requiem, revived interest in this composer.

A promising affiliation with what is now the Orchestre National de Lyon, begun in 1969, was soon terminated because in the same year Frémaux was appointed to the City of Birmingham Symphony Orchestra. He inherited a drastically underfunded, often fractious ensemble – its former leader Felix Kok recalled that in the 60s, under Hugo Rignold, when Kok asked the other violinists to follow his bowings they laughed at him.

It says much for Frémaux’s persuasive powers that he immediately achieved miraculous results, especially in French music. The British premiere of Cinq Métaboles (1965) by Henri Dutilleux at his debut concert as principal conductor in September 1969 sent critics into ecstasy. Besides the staples of Ravel, Debussy, Fauré and contemporaries, Frémaux tackled the big Berlioz beasts such as La Damnation de Faust and the Grande Messe des Morts, helped by his creation in 1973 of the CBSO Chorus, trained by Gordon Clinton, principal of Birmingham School of Music.

Described by one critic as “gnarled and handsome”, Frémaux was admired for his flair, his wristy baton technique and the way he virtually danced on the podium. He proved expert in marshalling such massive challenges as Saint-Saëns’s Organ Symphony and Holst’s The Planets. From 1970 the orchestra recorded for EMI – Warner Classics will issue a box of the complete Frémaux/CBSO output on 21 April – and by the next year concert attendances had risen from 67 to 83%.

Frémaux took the orchestra much more often to London and increased out-of-town appearances. In 1972 he and the CBSO toured eastern Europe. The idea of a proper concert hall for Birmingham was mooted as early as 1970; the resulting Symphony Hall finally opened in 1991, during Simon Rattle’s tenure.

Although Frémaux was less admired in the Viennese classics than in the Romantics or his native repertoire, his performances of Beethoven’s Ninth Symphony were events. He was very serious about British music, not only the central composers – he was an expert Waltonian – but contemporary figures, among them Richard Rodney Bennett, John McCabe, Humphrey Searle, Wilfred Josephs, Anthony Gilbert, John Mayer and Nicola LeFanu.

Problems with the Musicians’ Union and activists within the CBSO began to surface in 1977. The players’ ire was mostly directed at the general manager, Arthur Baker, who also functioned as Frémaux’s agent. In February 1978 two key viola players left and the conductor, faced with Tippett’s tricky Ritual Dances, wanted a freelancing former sub-principal to lead the section temporarily. The players insisted on giving the job to one of their own, and Frémaux’s choice had to sit at the back. In March, as Frémaux struggled to give performances of Britten’s War Requiem and prepare an EMI recording of it, the ugly situation came to a head. Baker resigned and Frémaux followed suit.

His huge advances with the orchestra were quickly forgotten as the CBSO found an admired new young conductor in Rattle, and another manager. But it would be grossly unfair to see Frémaux’s nine years merely as an upbeat to the Rattle era. His achievements are there for all to hear, in the recordings. Outstanding among these were the Berlioz Grande Messe des Morts, the Fauré Requiem, Honegger’s Pacific 231 and McCabe’s Second Symphony.

The rumpus affected Frémaux’s French career but he continued to appear and record in Britain until the mid-1990s, conducting virtually all its orchestras, as well as English National Opera, with whom he recorded Gounod’s Roméo et Juliette. On Desert Island Discs in 1977 he chose Britten’s Fanfare from Les Illuminations as his favourite record, above his seven other discs, all of French music.

From 1979 he was associated with the Sydney Symphony Orchestra as principal and then principal guest conductor, premiering Peter Sculthorpe’s Mangrove. He also worked in Berlin, Tokyo and Rome, retiring in 2005 to Avaray in central France.

Frémaux was twice awarded the Croix de Guerre, and in 1969 was made a Chevalier de la Légion d’Honneur.

In 1948 he married Nicole Petitbon, with whom he had five children. She died in 1999. That year he married the CBSO cellist Cécily Hake. One son, Patrick, predeceased him. He is survived by Cécily, his children Sylvain, Pascal, Vincent and Caroline, 11 grandchildren and three great-grandchildren.